You're also able to analyse the link you have created. This will let you see how many people have visited it, what country they're from and what time they visited it at amongst other things.
goo.gl is Google's link shortening service, which performs the same as above, but with the site goo.gl instead of bit.ly.
http://www.flickr.com/photos/71961694@N04/sets/ becomes http://bit.ly/zm8VaQ, which I then customise to http://bit.ly/int2pics. They all lead to the same site; by shortening the links, you're effectively just re-directing the users to the site you want them to visit, under the guise of your bit.ly site.